chalk

chalk teaches by showing you. On your Mac, hold ⌘⌥ and ask about anything on your screen: chalk answers out loud, marks the real button, and walks you through one step at a time. Or say what you want to learn, and it draws you a board, plans a course of classes you do (not just read), or takes you through a whole project in stages. It writes up your lectures against your slides, too. Boards and courses work in any browser. Free to start.